The Hall Effect and Dynamical Scaling about the Quantum Critical Point in Elemental Chromium

Elemental chromium is a spin-density-wave (SDW) antiferromagnet that can be tuned through a second order quantum phase transition by the application of 10 GPa of pressure. A nesting condition in the paramagnetic Fermi surface partially gaps the Fermi surface and forms the SDW. Since the Hall coefficient directly probes properties of the Fermi surface, it is an effective tool to investigate the evolution of the Fermi surface in the quantum critical regime, where there are indications of strong-coupling physics. In the low temperature limit, the Hall coefficient varies rapidly with pressure across the quantum critical point. By extending this measurement to higher temperatures, we are able to track the P-T dependence of this crossover and test analogies to the pseudogap phase in the superconducting cuprates. The temperature dependence of the width of this crossover constrains theories of dynamical scaling at the quantum critical point.